Means for controlling electric currents.



PATENTED MAY 23, 1905.

G. J. DORMAN.

MEANS FOR CONTROLLING ELECTRIC CURREN'IS.

APPLIOATIOI FILED 00T- 16,1902.

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M ATTORNEY UNITED STATES Patented May 23, 1905.

PATENT OFFICE.

GERALD J. DORMAN, OF BROOKLYN, NEW YORK, ASSIGNOR TO CONSOLI- DATED RAILIVAY ELECTRIC LIGHTING AND EQUIPMENT COMPANY.

MEANS FOR CONTROLLING ELECTRIC CURRENTS.

- SPECIFICATION forming part of Letters Patent No. 790,819, dated May 23, 1905.

I Application filed October 16, 1902. Serial No. 127,510,

To (1/7/71 whom it may concern:

Be it known that I, GERALD J. DORMAN, a citizen of the United States, residing in the borough of Brooklyn, in the county of Kings,

5 in the city and State of New York, have invented certain new and useful Improvements in Means for Controlling Electric Currents, of which the following is a specification.

This invention relates to means or devices for controlling electric currents generated by a dynamo, and especially to such means when used in connection with a dynamo and an external circuit fed by said dynamo and containing an accumulator and a series of lamps x 5 under circumstances where the dynamo is subject to variations in speed as in car-lighting, for example. In patents heretofore granted for electrical car-lighting devices the objects to be attained and the ditficulties to be overcome have been quite fully set forth, and for this reason it will not be necessary to go minutely into the same herein.

It will sufiice to say that the purpose of the present invention is to provide automatic 2 5 means for regulating the current in the circuits fed by the dynamo in order to maintain the current substantially uniform at the lamps and to adapt it automatically to altered conditions. In the present invention this is etfected, mainly, by means of compressed air and suitable valves therefor controlled and actuated by solenoids.

In the accompanying drawings, which illustrate an embodiment of the invention, Figure 3 5 1 is a view, mainly diagrammatic, illustrating the entire system of controlling devices. Fig. 2 is an end view of the air-valves. Figs. 3 and 4 are cross-sections of the valve B, showing the ports. Fig. 5 is a detail view of the 4 lamp-rheostat.

I) designates a dynamo the armature of which is or may be on and rotating with the axle of a railway-car to be lighted.

Fis the field-magnet coil of said dynamo.

A is an accumulator supplied or charged by the dynamo.

L designates lamps to be supplied by the dynamo and accumulator.

The ultimate purpose or object is to supply the lamps regularly under all the varying conditions.

In a circuit C, which includes the coil F of the field-magnet, is a rheostat R for putting more or less resistance in said circuit, and a is the coil of a solenoid S, the core Z) of which actuates the contact-arm 0 of the rheostat B through means now to be described. The arm 0 of the rheostat R turns about a center (Z and is secured to a toothed wheel a, which turns about the same center or axis. A toothed rack f gears with the wheel (1 and is connected with and carried by a piston-rod 1, carrying a piston it, which plays in a cylinder '2". The movement of the piston in the cylinder rotates the wheel e, and thus causes the arm 0 to traverse the circular series of contacts of the rheostat R, and thus shift more or less resistance into the field-circuit C. To move the piston to and fro in the cylinder, compressed air or other fluid is employed, the admission of the air to the cylinder being controlled by a cock or valve which is actuated by the core Z) of the solenoid. This valve (designated as a whole by B) comprises a suitable body or casing j, in which rocks a ported plug 70, coupled to the core of the solenoid by a link or rod M. Then the core is moved downward by the current flowing through the coil (0, the plug 7': is turned or rocked in one direction, and when this current is too weak to overcome the resistance offered by a spring 12, attached to the other extremity of the core 7), the said spring will retract the core, and thus rock the valve-plug in the opposite direction. The respective upper and lower ends of the cylinder 11 are connected with the casing of the valve B by pipes or tubes 0 and 0. In the plug is are an inlet-port p and exhaustport 9, adapted to connect with the pipe 0, and an inlet-pipe p and exhaust-port (1, adapted to connect with the pipe 0. These ports in the plug are so disposed that when the inlet-portp is open to the pipe 0 the exhaust-port q will be open to the pipe 0 and when the inlet-port p is open to the pipe 0 the exhaust-port q will be open to the pipe 0. The exhaust-ports q and q open to the atmosphere through the walls of the casingy', and the ports 1) and connect with an air-inlet from the source of supply. This source may be from the air-brake supply ot' the train.

The air-supply to the valve B is controlled by a valve or cook B, the ported plugs of which is rocked by coupling a crank-pin t thereon to the core 6 of a solenoid S, the coil a of which is in a shunt-circuit G from the main dynamo-circuit C in which is the coil (0 of the solenoid S. The core 6' has a spring 01/, which holds the cock B normally closed.

.So far as described the operation is as follows: The arm 0 of the rheostat R stands, as seen in Fig. 1, so as to cut out all resistance from the field-circuit C when the system is not in operation, and at such time the cock B will be closed and the valve B so set as to open pipe 0 to the exhaust and pipe 0 to the air-inlet. When the dynamo is started, the current in the shunt-circuit C causes the core 7) of the solenoid S to move down and open the cock B, thus admitting compressed air to the valve B from the supply-inlet G. When the current ,flowing through the coil of the solenoid S rises above the normal, it will eventually overcome the spring a and move the core I) of the solenoid downward, thus actuating the ported plug of the valve B in a manner to open the upper end of the cylinder to the compressed air and the lower end thereof to the atmosphere. This will have the effeet to drive down the piston it and through the rack and pinion to move the arm 0 of the rheostat R ahead and throw into the fieldcircuit C a certain amount of resistance. This will permit the spring a to again overcome the pull on the core 6 and move the latter upward, thus shifting the valve B in the other direction. When the current is normal, the valve B will cut off the entry of air to the cylinder both above and below the piston therein, and when it is below normal the compressed air will be admitted below the piston.

The cock B is merely designed to cut off the compressed air when the generator is not running.

H is an automatic switch to connect the accumulator with the generator or dynamo. This device comprises an armature a, pivotally mounted at a and having a spring 14 and two magnets o and 0), so disposed as to attract said armature, the magnet n being in shunt with the dynamo and the magnet o in series between the dynamo and accumulator. A break in the circuit between the dynamo and accumulator is adapted to be closed by a movable terminal contact w on the armature a, being put in touch with a fixed terminal contact w when the magneto is energized and the armature thereby attracted. Normally a contact (01' pair of contacts) as on the armature dips into a pair of mercury-cupsw, forming terminals in a circuit for short-circuiting the rheostat R in the lamp-circuit and in series with the lamps.

The operation of the switch H is as follows: When the voltage of the generator becomes equal to that of the accumulator, the shuntmagnet 42 will be energized sufficiently to attract the armature u by overcoming its spring a thus breaking the short circuit at was and closing the break in the circuit at w 20', thus connecting the accumulator and generator.

S is a solenoid the coil (0 of which is in series with thelamps L. The core 5 of this solenoid has a spring a and is coupled by a link or stem m with the arm 0 of the rheostat R. When any number of lamps are turned on, the current they take energizes the core of the solenoid S and causes it to move, as here shown, downward against the resistance of the spring 91 This movement of the core acts on the arm 0 of the rheostat in a manner to cut out resistance in proportion to the number of lamps turned on, which increases or diminishes the current flowing through the solenoid-coil. To permit a free movement of the arm 0' of the rheostat R, the said arm is provided with V-edged rollercontacts g, which bear on and roll in V-shaped grooves in the contacts 2 on the rheostat. This is illustrated in Fig. 5. The importance of this lamp resistance is to cut down the extra voltage to which the accumulator rises when being charged by the dynamo. The amount of resistance required depends on the number of lamps turned on, and hence the importance of employing an automatically-regulable resistance operated by some medium which is acted upon directly by the energy employed. In other cases where lamp resistance is used this feature has not, so far as I am aware, been considered sufliciently, as they employ the same resistance without reference to the number of lamps turned on.

It will be noted that in the construction of the regulator herein described the use of an electric or other motor is dispensed with, the power for actuating the field-rheostat being derived from -compressed air taken from the train-pipe of the air-brakes on the car.

Having thus described my invention, I claim 1. In a device for controlling electric currents, the combination with a dynamo, a main exterior circuit fed by said dynamo, a fieldmagnet circuit of the dynamo, and a rheostat in said circuit, said rheostat having a movable contact-arm which turns radially about a center, of a cylinder, a piston therein, a rod connected with said piston, a toothed rack connected operatively with said piston-rod and movable therewith, a toothed wheel connected to and turning with the arm of the rheostat, whereby reciprocation of the piston imparts rotary movement to said arm, means for supplying compressed air to said cylinder for operating the piston, a solenoid having its coil in the main dynamo-circuit, and means actuated by the core of said solenoid which conlator, whereby when the voltage of the dynamo falls below normal the circuit will be broken between the dynamo and accumulator and the lamp resistance short-circuited.

In witness whereof I have hereunto signed my name, this 13th day of October, 1902, in the presence of two subscribing witnesses.

GERALD J. DORMAN.

Witnesses:

HENRY CoNNE'rT, PETER A. Ross. 

